1. Field of the Invention
The present invention relates to a semiconductor light-emitting device which has a planar type PN junction or a Schottky junction and produces a light by applying a reverse bias to the junction to cause an avalanche breakdown.
2. Related Background Art
Photo-emission from avalanche breakdown has been reported by an article "Photo emission from avalanche breakdown" by A. G. Chynoweth and H. K. Mckey, Phys. Rev., Vol. 102, p.369, 1956. On the other hand, an application of the photo emission phenomenon to a light emitting semiconductor element is reported in "A study of the nature and characteristics of light radiation in reverse-biased silicon junctions" by C. B. Williams and K. Daneshver, Conf. Proc. IEEE, p.161, 1988. In this article, it is reported that a photo emission intensity on a Si PN junction interface is 0.01 W/cm.sup.2. The semiconductor devices in those articles comprise planar type PN junctions as described in "Physics of Semiconductor Devices" by S. M. Sze, John Wiley & Sons, p. 73.
In the prior art devices, because of the planar type PN junction, there exists a portion having a cylindrical radius of curvature or spherical radius of curvature around the junction. Since an electric field acting on the junction is higher in the portion having the cylindrical or spherical radius of curvature than in a planar junction portion, the photo emission by the avalanche breakdown occurs only in the high electric field zone, that is, only in the periphery of the junction, and it is not possible to uniformly emit light throughout the junction. In such a planar junction, there occurs photo-emission by an electric field concentration due to ununiformity of a paterning shape in the formation of the junction or photo-emission by an electric field concentration due to defects. Thus, photo-emission by inadvertent factors governs the light intensity of the photo emission or the position of the photo emission. Accordingly, it is not possible to form a light emitting device with a high control.